Osmotic Pressure

Question

Calculate the osmotic pressure of a solution containing 0.936 moles of methanol (CH₃OH: nonelectrolyte) in 300. mL of soution at 25.0 degrees celsius. 

Answer 1

The expression for osmotic pressure is π = iMRT

π = osmotic pressure = ?

i = van't Hoff factor = 1 for CH3OH, since it is a non electrolyte

M = molarity = mols / L = 0.936 g CH3OH x 1 mol / 32.0 g = 0.02925 mols / 0.300 L = 0.0975 M

R = gas constant = 0.0821 Latm / Kmol

T = temperature in K = 25.0ºC + 273 = 298K

Solving for π

π = (1)(0.0975)(0.0821)(298)

π = 2.39 atm